Control mechanism for influencing the needle of an ornamental stitch sewing machine



June 6, 1951 U E 2,987,020

CONTROL MECHANISM FOR INFLUENCING THE NEEDLE OF AN ORNAMENTAL STITCH SEWING MACHINE Filed April 8, 1959 2 Sheets-Sheet 1 INVENTOP Eric/7 GRUN/(E June 6, 1961 E. GRUNKE 2,937,020

CONTROL MECHANISM FOR INFLUENCING THE NEEDLE OF AN ORNAMENTAL STITCH SEWING MACHINE 2 Sheets-Sheet 2 Filed April 8, 1959 INVENTOIP Eric 1 GRUNA E United States Patent CONTROL MECHANISM FOR INFLUENCING THE NEEDLE OF AN ORNAMENTAL STITCH SEW- ING MACHINE Erich Griinke, Hinwil, Zurich, Switzerland, assignor to G. M. Pfatf A.G., Kaiserslautern, Pfalz, Germany Filed Apr. 8, 1959, Ser. No. 805,060 Claims priority, application Switzerland Apr. 10, 1958 7 Claims. (.Cl; 112-219) This invention relates to improvements. of sewing machines, and concerns more, particularly a sewing machine whose operation may be stopped at or in a predetermined position relative to the main drive shaft of the machine.

A sewing machine equipped with means for stopping the machine has. been known in specially constructed machines for this purpose. Machines of this kind perform a sewing operation in any desired sequence of, say, four stitches and in such a manner that when the machine is stopped the already initiated four stitch cycle will be terminated. and finished, whereafter the machine becomes automatically checked and halted. The stoppage of the machine occurs then in a predetermined position of the needle. Such operational working phase requires, however, a relatively complicated and specialized mechanism.

In sewing machines equipped to perform and produce ornamental stitchpatterns it was heretofore not possible. after a great number of equal stitch patterns created. in uninterrupted sequence to stop the sewing machine at a. preselected time upon finishing the respective ornamental stitch pattern. To employ or apply devices heretofore known for special sewing machines to so-called house hold or ornamental stitch sewing machines was. not considered suitable due to its complicated mechanism;

The present invention has as one of its objects-to: pro?- vide means eliminating any complicated. stop mechanism and contemplates in connection with household sewing machines to employ a system or arrangement on such machine type that it may be readily and automatically stopped at any desirable. time which the sewing operator may choose, for instance, at the end of a stitch pattern.

It is therefore another object of this invention to pro vide means afifording the construction of a compactv device whichis easily operable, brings about considerableadvantages in the operation of a sewing machine, may be built at relatively low cost and constitutes a greatly simplified lever-actuated arrangement which is in easy reachof the operator,

It is still another object of the present invention to provide means ensuring great accuracy, efliciency and economy in manipulation and application to heretofore existing sewing machines of the aforesaid type and also complying with: all principal requirements of the practice.

Still a further object of the present invention resides in the provision of means enabling the operator to stop the sewing machine operation at any desired time and without damage to the machine needle or to the stitch pattern work performed by it.

In accordance with the invention the rotating drive shaft of the ornament or stitch pattern producing mechanism, which shaft runs at greatly reduced speed relative to the main machine drive shaft is employed as a control shaft for causing interruption or stoppage of the needle operation.

Surprisingly a rather simple arrangement sufiices in order to bring about a stopping device of suificient accuracy at the end of a stitch formation or pattern.

These and other objects of the invention will become further apparent from the following detailed description,

21 reference being made to the accompanying drawings showing a preferred embodiment of the invention.

In the drawings:

FIG. 1 shows schematically a device embodying the, present invention and seen in operative position just prior to the stoppage thereof;

FIG. 2 shows the device of FIG, 1 in an analogous position after stoppage has occurred;

FIG. 3 shows again schematically the device of FIG. 1 in. another position for automatic stoppage and for assuming an inoperative position;

FIG. 4 is a fragmentary top plan view of the device, as seen in FIG. 1; and- FIG. 5 is a complete view similar to that of FIG. 2.

FIG. 6 is an end elevational view of FIG. 5.

Referring now more particularly to the drawings, there is disclosed a portion of a sewingmachine having a handwheel 1 which is operatively connected to the drive shaft Ia of the machine,

This drive shaft may be brought into driving relation with a shaft 2 via a friction wheel 3, said shaft, 2 constituting, a control shaft being driven by a motor (not shown). This motor as the same is mounted on oscillatory frame 4, whose outline is indicated in dot and dash lines, presses with sufficient force due to its Weight friction cone 3 against surface 1b of wheel. 1. Frame 4, as shown, is pivotally supported at fulcrum. 5. mounted on the housing of the machine and has bearings 2a andv 2b for mounting the shaft 2. On this housing (not shown) is also secured a carrier member 8a which carr ies. a bolt 8. A. control element or lever 6 is rockably mounted about the bolt 8. A detent 7a is provided on a carrier 7b which latter is secured to the housing. The lever 6 is retained in its inoperative and operative positions, respectively, by means of a ball 7 which engages in depressions or recesses 70, respectively, provided in the lever. 6. The ball 7 is urged into the respective depression 70 by means of a spring (not shown) provided withinthe hollow interior of the detent 7a.

To this control or actuating lever 6 is connected at fulcrum 9 a. triangular-shaped member 10, which during its; inoperativeposition or position of rest is seated against and abuts striker pin 11 of lever 6. There is further journaledin the machine frame (not shown for the sake of clarity) a rotatable cam disk 12 having a cam or nose 13, which is adapted to cooperate with a central pin 14 carried by member 10.

The bearing 2a of the oscillatory frame 4 is provided with a regulator pin 15 for a purpose about to be described.

The operation of the aforesaid lever assembly is as follows:

According, to FIG. 1 the cam disc 12 is driven and rotated counter-clockwise according to arrow A and the position of said disc is illustrated immediately prior to the abutment of its cam or nose 13 against pin 14.

According to FIG. 2 cam. disk 12 is further rotated a predetermined distance and its cam 13 has somewhat displaced and lifted pin '14 of triangular member or lever 10.. This latter member 10 rotates about fulcrum 9 and comes to. displace pin 15 of the oscillatory frame 4, which latter inturn swings about fixed, fulcrum 5 against the direction of arrow B (in counter-clockwise direction), whereby frame 4 with support 2a, pin 15, shaft 2 and friction cone 3 are moved away from wheel 1, so that the frictional or coupling connection between conical frictional wheel 3 and contiguous surface 1b of hand wheel 1 is interrupted, thus the drive from the motor seated on frame 4 and the motion of the essential, operative or oscillatory elements or parts of the sewing needle of the sewing machine come to an immediate stop.

Consequently, by suitably adjusting the control handle 6 it is readily apparent that one can easily regulate or influence the stitch pattern at its end or its start in a very efficacious manner and by means of a device which requires only a few operable parts. If control handle 6 -is displaced into position of FIG. 3 then pin 14 of triangular lever 10 is brought out of reach of cam 13 of cam disk 12 which cannot anymore abut against the pin 14, the latter being thus located midway between adjustable fulcrum 9 and abutment pin 15 on frame 4. The sewing machine may be thus completely disconnected from the aforesaid control mechanism and can thereafter carry out the stitch pattern for which the machine has been set, until control or actuating means 6 is again swung from a position as seen in FIG. 3 into a position illustrated in FIGS. 1 or 5, respectively. As seen in FIG. frame 4 is swung about fulcrum 5 for disengaging friction wheel 3 from wheel 1.

It is well understood that instead of a hand-actuated lever or handle 6 any electrically operated-device may be employed, replacing handle 6, such as suitable electric relays or an armature actuated by a solenoid to bring about the respective positions of lever 10 and its pin '14 relative to cam disk 12 and cam 13.

Lever 6 is swingable about pivot pin 8 (FIG. 2) and as lever 10 is triangular in shape one of its edges 10a may be shaped for seating abutment pin 15 on one end of the oscillatory frame 4. It is to be noted that friction wheel 3 and contiguous part 1b of handwheel 1 form coupling means to interconnect the control shaft with the drive shaft 1a.

It can thus be seen that there has been provided according to the invention a novel regulator arrangement for interrupting operation of the machine during its stitch pattern performance, which arrangement is of extreme simplicity, highly desirable and effective and may be readily built in heretofore existing normal stitch pattern sewing machines.

Various changes and modifications may be made without departing from the spirit and scope of the present in-.

connected to said frame, lever means operatively oonnected with said actuating means, whereby said lever means may be swung by said actuating means into operative and inoperative positions, respectively, said lever means carrying a first abutment pin, a power driven rotatable cam disc provided with a cam for cooperation with said first abutment pin, a control shaft, a friction wheel on one end of said control shaft and frictionally engageable with a portion of said handwheel, to translate rotational movement to said drive shaft, said swingable frame being connected to said control shaft, said fulcrum pivotally supporting one end of said frame, whereby the latter may move about said fulcrum for operating said friction Wheel, a second abutment pin on the other end of said frame, said second abutment pin being adapted to cooperate with said lever means, so that said friction wheel may be moved into and out of engagement with said handwheel portion, respectively, when said frame with said control shaft is pivoted about said fulcrum upon engagement of said second abutment pin with said lever means caused by said actuating means, and when said first abutment is engaged by said cam of said cam disc.

2. In a machine according to claim 1, including a pivot establishing pivotal connection of said actuating means and located a predetermined distance from said first abutment pin, whereby the latter may be moved out or reach of said cam upon pivotal movement of said actulever means forming a transmission means between the cam of the cam disk and said second abutment pin for displacing said friction wheel relative to said handwheel portion.

5. In a machine according to claim 4, said triangular lever means being provided with a recessed edge for seating thereagainst said second abutment pin.

6. A control mechanism for influencing the needle of a stitch pattern and like household sewing machine having a first shaft and a handwheel connected thereto;

" comprising frame means, actuating means provided with a pivot swingably connecting said actuating means to said frame means triangular lever means operatively connected with said actuating means, whereby said lever means may be swung by said actuating means into operative and inoperative positions, respectively, a first fulcrum adjustably connecting said lever means to said actuating means, said lever means carrying a first abutment pin, a rotatable cam disk provided with a cam adapted to engage said first abutment pin, a second shaft, coupling means on said second shaft and on a portion of said handwheelof said first shaft, thereby to translate rotational movement to said first shaft and to interrupt said movement, said second shaft being mounted on said frame means, said frame means including at one end a second fulcrum for pivotally supporting said frame means, whereby the latter may move about said second fulcrum for operating said coupling, a second abutment pin on the other end of said 'frame means, said second abutment pin being displaceable via said lever means by said actuating means, thereby to move said coupling means into and out of engagement with said first shaft, respectively, when said frame means is pivoted with said second shaft upon engagement of said second abutment pin with said lever means and upon engagement of said first abutment pin with said cam of said cam disk.

7.' A control mechanism according to claim 6, said lever means being shaped to provide a seat for accommodating s'aidsecond abutment pin.

References Cited in the file of this patent UNITED STATES PATENTS 1,181,766 Hill' May 2, 1916 1,185,092 Head May 30, 1916 FOREIGN PATENTS 9,236 Great Britain of 1913 1,032,251 France Mar. 25, 1953 

